Carotid occlusion of a giant intracavernous aneurysm on a single functional internal carotid artery.

The prevalence of intracranial aneurysms (IA) is higher in patients with stenosis of the internal carotid artery (ICA), the intracavernous internal carotid aneurysm is an intracranial aneurysm causing major functional and vital complications. We report the case of a 26-year-old man who consulted for a reduction in visual acuity, converging strabismus and ptosis of the right eye evolving for 7 months before his consultation, the various neuro-radiological examinations made it possible to identify diagnose a giant aneurysm of the right intracavernous internal carotid artery associated with severe stenosis of the contralateral internal carotid artery, hence the performance of a therapeutic arteriography consisting of an occlusion of this aneurysm. In summary, we describe successful management of a giant aneurysm of the intracavernous portion of a single functional internal carotid artery, while preserving optimal cerebral vascularization.

Primary umbilical endometriosis: Surgical case report.

Introduction: Endometriosis is a benign nevertheless a chronic condition which impacts greatly the quality of life through cyclic discomfort. We aim to report the case of umbilical endometriosis and a literature review of the different treatment modalities. Case Report: This was a case of a 43-year-old woman, with no history, who presented with a painful hemorrhagic umbilical swelling during the menstrual period associated with dysmenorrhea. Abdominal ultrasound revealed a subcutaneous umbilical mass of non-vascularized tissue nature confirmed on Doppler. Pelvic MRI which confirms the diagnosis of primary umbilical endometriosis. The patient underwent wide local excision of the endometriotic nodule with umbilical reconstruction. Histology confirmed the diagnosis of umbilical endometriosis. Resection margins were clear. Discussion: Extra-pelvic endometriosis sites are not common, especially the umbilicus. It usually occurs secondary to surgical scars, specifically after laparoscopy or open abdominal surgery. Surgical management is currently described as gold standard. Laparoscopic approach is recommended as it allows better visual inspection for secondary localization of endometriosis. Medical management corresponds to combined oral contraceptives (COCs) or progestins for management of endometriotic implants decreasing inflammatory effects, or Gonadotropin-releasing hormone for long-course treatment. Malignant transformation of the umbilical nodule has been described in literature with a reported risk of malignant transformation to be 3%. Conclusion: Current management of extragenital endometriosis suggest radical surgery with wide local excision. Due to the rarity, there is a paucity of data on umbilical endometriosis and mostly reported from case reports.

Non-Trivial Dynamics in the FizHugh-Rinzel Model and Non-Homogeneous Oscillatory-Excitable Reaction-Diffusions Systems.

This article focuses on the qualitative analysis of complex dynamics arising in a few mathematical models in neuroscience context. We first discuss the dynamics arising in the three-dimensional FitzHugh-Rinzel (FHR) model and then illustrate those arising in a class of non-homogeneous FitzHugh-Nagumo (Nh-FHN) reaction-diffusion systems. FHR and Nh-FHN models can be used to generate relevant complex dynamics and wave-propagation phenomena in neuroscience context. Such complex dynamics include canards, mixed-mode oscillations (MMOs), Hopf-bifurcations and their spatially extended counterpart. Our article highlights original methods to characterize these complex dynamics and how they emerge in ordinary differential equations and spatially extended models.

The generation of diverse traveling pulses and its solution scheme in an excitable slow-fast dynamics.

In this article, we report on the generation and propagation of traveling pulses in a homogeneous network of diffusively coupled, excitable, slow-fast dynamical neurons. The spatially extended system is modeled using the nearest neighbor coupling theory, in which the diffusion part measures the spatial distribution of coupling topology. We derive analytically the conditions for traveling wave profiles that allow the construction of the shape of traveling nerve impulses. The analytical and numerical results are used to explore the nature of propagating pulses. The symmetric or asymmetric nature of traveling pulses is characterized, and the wave velocity is derived as a function of system parameters. Moreover, we present our results for an extended excitable medium by considering a slow-fast biophysical model with a homogeneous, diffusive coupling that can exhibit various traveling pulses. The appearance of series of pulses is an interesting phenomenon from biophysical and dynamical perspective. Varying the perturbation and coupling parameters, we observe the propagation of activities with various amplitude modulations and transition phases of different wave profiles that affect the speed of pulses in certain parameter regimes. We observe different types of traveling pulses, such as envelope solitons and multi-bump solutions, and show how system parameters and coupling play a major role in the formation of different traveling pulses. Finally, we obtain the conditions for stable and unstable plane waves.

Mathematical modeling of COVID-19 pandemic in the context of sub-Saharan Africa: a short-term forecasting in Cameroon and Gabon.

In this paper, we propose and analyse a compartmental model of COVID-19 to predict and control the outbreak. We first formulate a comprehensive mathematical model for the dynamical transmission of COVID-19 in the context of sub-Saharan Africa. We provide the basic properties of the model and compute the basic reproduction number $\mathcal {R}_0$ when the parameter values are constant. After, assuming continuous measurement of the weekly number of newly COVID-19 detected cases, newly deceased individuals and newly recovered individuals, the Ensemble of Kalman filter (EnKf) approach is used to estimate the unmeasured variables and unknown parameters, which are assumed to be time-dependent using real data of COVID-19. We calibrated the proposed model to fit the weekly data in Cameroon and Gabon before, during and after the lockdown. We present the forecasts of the current pandemic in these countries using the estimated parameter values and the estimated variables as initial conditions. During the estimation period, our findings suggest that $\mathcal {R}_0 \approx 1.8377 $ in Cameroon, while $\mathcal {R}_0 \approx 1.0379$ in Gabon meaning that the disease will not die out without any control measures in theses countries. Also, the number of undetected cases remains high in both countries, which could be the source of the new wave of COVID-19 pandemic. Short-term predictions firstly show that one can use the EnKf to predict the COVID-19 in Sub-Saharan Africa and that the second vague of the COVID-19 pandemic will still increase in the future in Gabon and in Cameroon. A comparison between the basic reproduction number from human individuals $\mathcal {R}_{0h}$ and from the SARS-CoV-2 in the environment $\mathcal {R}_{0v}$ has been done in Cameroon and Gabon. A comparative study during the estimation period shows that the transmissions from the free SARS-CoV-2 in the environment is greater than that from the infected individuals in Cameroon with $\mathcal {R}_{0h}$ = 0.05721 and $\mathcal {R}_{0v}$ = 1.78051. This imply that Cameroonian apply distancing measures between individual more than with the free SARS-CoV-2 in the environment. But, the opposite is observed in Gabon with $\mathcal {R}_{0h}$ = 0.63899 and $\mathcal {R}_{0v}$ = 0.39894. So, it is important to increase the awareness campaigns to reduce contacts from individual to individual in Gabon. However, long-term predictions reveal that the COVID-19 detected cases will play an important role in the spread of the disease. Further, we found that there is a necessity to increase timely the surveillance by using an awareness program and a detection process, and the eradication of the pandemic is highly dependent on the control measures taken by each government.

On the Modeling of the Three Types of Non-spiking Neurons of the Caenorhabditis elegans.

The nematode Caenorhabditis elegans (C. elegans) is a well-known model organism in neuroscience. The relative simplicity of its nervous system, made up of few hundred neurons, shares some essential features with more sophisticated nervous systems, including the human one. If we are able to fully characterize the nervous system of this organism, we will be one step closer to understanding the mechanisms underlying the behavior of living things. Following a recently conducted electrophysiological survey on different C. elegans neurons, this paper aims at modeling the three non-spiking RIM, AIY and AFD neurons (arbitrarily named with three upper case letters by convention). To date, they represent the three possible forms of non-spiking neuronal responses of the C. elegans. To achieve this objective, we propose a conductance-based neuron model adapted to the electrophysiological features of each neuron. These features are based on current biological research and a series of in-silico experiments which use differential evolution to fit the model to experimental data. From the obtained results, we formulate a series of biological hypotheses regarding currents involved in the neuron dynamics. These models reproduce experimental data with a high degree of accuracy while being biologically consistent with state-of-the-art research.

On a Coupled Time-Dependent SIR Models Fitting with New York and New-Jersey States COVID-19 Data.

This article describes a simple Susceptible Infected Recovered (SIR) model fitting with COVID-19 data for the month of March 2020 in New York (NY) state. The model is a classical SIR, but is non-autonomous; the rate of susceptible people becoming infected is adjusted over time in order to fit the available data. The death rate is also secondarily adjusted. Our fitting is made under the assumption that due to limiting number of tests, a large part of the infected population has not been tested positive. In the last part, we extend the model to take into account the daily fluxes between New Jersey (NJ) and NY states and fit the data for both states. Our simple model fits the available data, and illustrates typical dynamics of the disease: exponential increase, apex and decrease. The model highlights a decrease in the transmission rate over the period which gives a quantitative illustration about how lockdown policies reduce the spread of the pandemic. The coupled model with NY and NJ states shows a wave in NJ following the NY wave, illustrating the mechanism of spread from one attractive hot spot to its neighbor.

Diffusion dynamics of a conductance-based neuronal population.

We study the spatiotemporal dynamics of a conductance-based neuronal cable. The processes of one-dimensional (1D) and 2D diffusion are considered for a single variable, which is the membrane voltage. A 2D Morris-Lecar (ML) model is introduced to investigate the nonlinear responses of an excitable conductance-based neuronal cable. We explore the parameter space of the uncoupled ML model and, based on the bifurcation diagram (as a function of stimulus current), we analyze the 1D diffusion dynamics in three regimes: phasic spiking, coexistence states (tonic spiking and phasic spiking exist together), and a quiescent state. We show (depending on parameters) that the diffusive system may generate regular and irregular bursting or spiking behavior. Further, we explore a 2D diffusion acting on the membrane voltage, where striped and hexagonlike patterns can be observed. To validate our numerical results and check the stability of the existing patterns generated by 2D diffusion, we use amplitude equations based on multiple-scale analysis. We incorporate 1D diffusion in an extended 3D version of the ML model, in which irregular bursting emerges for a certain diffusion strength. The generated patterns may have potential applications in nonlinear neuronal responses and signal transmission.

[Acute lower limb ischemia secondary to femoral osteochondroma]. / Ischémie aiguë du membre inférieur secondaire à un ostéochondrome fémoral.

Osteochondromas or bone exostoses are bone tumors commonly found in adolescents or young adults. These benign tumors are usually incidentally discovered, exceptionally by a vascular or nervous complication. We report the case of a 22-year-old patient presenting with left femoral exostosis revealed by an acute ischemia of the lower limb. Clinical examination of the contralateral limb was without abnormality. Computed tomography angiography revealed a thrombosed aneurysm of the supra articular popliteal artery associated to an exostosis of the lower extremity of the femur. Surgical treatment was recommended in this patient: resection of the popliteal aneurysm associated with a end-to-end suture of the popliteal artery and resection of bone exostosis.

Permanence and Extinction of a Diffusive Predator-Prey Model with Robin Boundary Conditions.

The main concern of this paper is to study the dynamic of a predator-prey system with diffusion. It incorporates the Holling-type-II and a modified Leslie-Gower functional responses under Robin boundary conditions. More concretely, we study the dissipativeness of the system by using the comparison principle, and we derive a criteria for permanence and for predator extinction.

Rare variant of metaplastic carcinoma of the breast: a case report and review of the literature.

BACKGROUND: Metaplastic carcinoma encompasses a group of neoplasms characterized by differentiation of the neoplastic epithelium into squamous cells and/or mesenchymal-looking elements. Spindle cell carcinoma is a rare variant of this special histological type. Its prognosis remains poor, with a high rate of local recurrence and distant metastasis. To date, only a small number of cases have been described. There is no clear agreement on this histological subtype. CASE PRESENTATION: We report a case of a 53-year-old Moroccan woman who consulted our institution following palpation of a nodule of the left breast. Mammography in combination with breast ultrasonography revealed a lesion classified as Breast Imaging Reporting and Data System 4 with microcalcification. The patient was diagnosed with spindle cell carcinoma of the breast. The diagnosis was based primarily on histological and immunohistochemical studies of the breast biopsy and secondarily on the surgical specimen. No local or distant metastasis was found. The treatment used was total surgical excision followed by radiotherapy. CONCLUSIONS: We describe the features (epidemiological, clinical, histological, immunohistochemical, and therapeutic outcomes) of our patient's case and compare them with literature data.

A network model for control of dengue epidemic using sterile insect technique.

In this paper, a network model has been proposed to control dengue disease transmission considering host-vector dynamics in n patches. The control of mosquitoes is performed by SIT. In SIT, the male insects are sterilized in the laboratory and released into the environment to control the number of offsprings. The basic reproduction number has been computed. The existence and stability of various states have been discussed. The bifurcation diagram has been plotted to show the existence and stability regions of disease-free and endemic states for an isolated patch. The critical level of sterile male mosquitoes has been obtained for the control of disease. The basic reproduction number for n patch network model has been computed. It is evident from numerical simulations that SIT control in one patch may control the disease in the network having two/three patches with suitable coupling among them.

Canard phenomenon in a slow-fast modified Leslie-Gower model.

Geometrical Singular Perturbation Theory has been successful to investigate a broad range of biological problems with different time scales. The aim of this paper is to apply this theory to a predator-prey model of modified Leslie-Gower type for which we consider that prey reproduces mush faster than predator. This naturally leads to introduce a small parameter ϵ which gives rise to a slow-fast system. This system has a special folded singularity which has not been analyzed in the classical work [15]. We use the blow-up technique to visualize the behavior near this fold point P. Outside of this region the dynamics are given by classical regular and singular perturbation theory. This allows to quantify geometrically the attractive limit-cycle with an error of O(ϵ) and shows that it exhibits the canard phenomenon while crossing P.

Coalescence of Macroscopic Flux Ropes at the Subsolar Magnetopause: Magnetospheric Multiscale Observations.

We report unambiguous in situ observation of the coalescence of macroscopic flux ropes by the magnetospheric multiscale (MMS) mission. Two coalescing flux ropes with sizes of ∼1 R_{E} were identified at the subsolar magnetopause by the occurrence of an asymmetric quadrupolar signature in the normal component of the magnetic field measured by the MMS spacecraft. An electron diffusion region (EDR) with a width of four local electron inertial lengths was embedded within the merging current sheet. The EDR was characterized by an intense parallel electric field, significant energy dissipation, and suprathermal electrons. Although the electrons were organized by a large guide field, the small observed electron pressure nongyrotropy may be sufficient to support a significant fraction of the parallel electric field within the EDR. Since the flux ropes are observed in the exhaust region, we suggest that secondary EDRs are formed further downstream of the primary reconnection line between the magnetosheath and magnetospheric fields.

Syndrome of inappropriate anti-diuresis induces volume-dependent hypercalciuria.

Hyponatremia is associated with bone demineralization. We hypothesized that, during hyponatremia, calciuria and calcium balance depend on volemic status. We evaluated calciuria in patients with hyponatremia, secondary to SIAD or hypovolemia. Patients with SIAD exhibited a volemic expansion that was associated with hypercalciuria. Calciuria was proportional to markers of volemia. INTRODUCTION: Chronic mild hyponatremia has been associated with bone demineralization of unknown mechanisms. During chronic hyponatremia, arginine-vasopressin secretion can result from hypovolemia or from syndrome of inappropriate anti-diuresis (SIAD) that leads to a slightly volemic expansion. Since volemia determines renal calcium excretion and balance, we evaluated calcium homeostasis in patients with chronic hyponatremia, related to SIAD or to hypovolemia. METHODS: We retrospectively included all patients referred to our Department between May 2006 and May 2014 for hyponatremia, resulting from SIAD or chronic hypovolemia. None had edema, cirrhosis, cardiac, or renal insufficiency. Exploration included estimation of volemia, extracellular fluid volume (ECFV) measurement with inulin, and calcium homeostasis. RESULTS: In total, the SIAD and hypovolemic groups included 22 and 7 patients, respectively. The SIAD group exhibited signs of increased volemia: higher glomerular filtration rate, higher fractional excretion of uric acid, and lower plasma renin. ECFV exceeded that of the hypovolemic group and was above usual values. There was no difference between the two groups regarding plasma calcium, PTH, and vitamin D. However, in the SIAD group, calciuria was higher than in the hypovolemic group, reaching levels of hypercalciuria. Furthermore, there was a positive correlation between calciuria and markers of volemia. CONCLUSIONS: Our results show that SIAD results in a volemic expansion tendency that is associated with a decrease in renal calcium reabsorption and thus hypercalciuria, whereas in the hypovolemic group, calciuria was not increased. Therefore, renal loss of calcium and bone demineralization in SIAD patients could be partly induced by volemic expansion.

[Fusarioses to Fusarium solani in an immunocompetent and immunocompromised diagnosed in military hospital of Rabat]. / Fusarioses superficielles à Fusarium solani chez un immunocompétent et un immunodéprimé diagnostiquées à l'Hôpital militaire de Rabat.

Fusarium are ubiquitous hyalohyphomycoses, usually encountered in the soil. They are the second unusual fungal pathogens after the Trichosporon. Intertrigo Fusarium sp. is a rare achievement. We report a case of intertrigos interorteils in an immunocompetent 45years old and a same case associated with a total onychodystrophy in an immunocompromised 75year-old. Laboratory diagnosis has found Fusarium solani confirmed with the positivity of a pure culture twice. Good progress was noted with terbinafine treatment. One or more aggravating factors must always be sought. These cases are in addition to cases increasingly frequent intertrigo due to Fusarium sp.

Basin of Attraction of Solutions with Pattern Formation in Slow-Fast Reaction-Diffusion Systems.

This article is devoted to the characterization of the basin of attraction of pattern solutions for some slow-fast reaction-diffusion systems with a symmetric property and an underlying oscillatory reaction part. We characterize some subsets of initial conditions that prevent the dynamical system to evolve asymptotically toward solutions which are homogeneous in space. We also perform numerical simulations that illustrate theoretical results and give rise to symmetric and non-symmetric pattern solutions. We obtain these last solutions by choosing particular random initial conditions.